This invention relates to a method and apparatus for encoding and decoding signals which may represent any continuous or discrete values.
It is well established that various types of signals can be efficiently encoded and subsequently decoded in a manner which substantially reduces the size of the information required (e.g. number of bits, bandwidth, or memory) without undue or noticeable degradation of the decoded signal. Examples are the types of audio and video bandwidth compression schemes that are currently in widespread use.
In signal analysis, it is often useful to recognize the appearance of characteristic frequencies, but this knowledge generally has to be coupled with the location of the time (or space) interval giving rise to the frequency. Such questions can usually be tackled by use of the windowed Fourier transform, with different size windows corresponding to the scale of the transient feature. This analysis can be achieved by correlating the signal to all windowed exponentials and checking for large correlations. Unfortunately, due to lack of independence, information obtained can be redundant and inefficient for feature reconstruction purposes.
It is among the objects of the present invention to provide an improved encoding and decoding method and apparatus which overcomes limitations of prior art techniques and provides improved and more efficient operation.